This invention relates to dispensers for multiple rolls of sheet material and, in one aspect, to dispensers for two rolls of paper towel.
Dispenser for rolls of flexible sheet material, such as paper towel rolls, are well known. Paper towel dispensers are widely used in public lavatories to dispense paper toweling for users to dry their hands. Such dispensers typically include either a crank or lever which the user operates to drive a feed mechanism for dispensing the paper toweling. The feed mechanism typically includes a drive roller rotated by a crank or lever or an idler or pressure roller, the paper toweling is fed through a nip between these two rollers and the pressure roller is spring loaded to provide sufficient friction for rotation of the drive roller to unwind the paper toweling off a roll core.
Some paper towel dispensing devices are capable of sequentially dispensing two rolls of paper toweling. This type dispenser includes a transfer mechanism arranged so that, when all the paper toweling from a primary roll has been dispensed, toweling from the reserve roll is introduced into the feed mechanism. One type transfer mechanisms includes a number of rollers which are arranged to provide tension between the paper toweling being unwound from the primary on the feed mechanism and, in response to loss of this tension, effect a transfer of paper toweling from the reserve roll into the feed mechanism. This loss of tension usually occurs when the tail end of the paper toweling has been completely unwound and detached from the primary roll core. However, a loss of tension occasionally can occur during normal use even though there is still paper on the primary roll. For example, if the primary roll core binds and the user is required to use additional force to operate the crank or lever, the primary roll can over run after the bind is broken loose. This can cause a slack condition which is the same as the loss tension to the transfer mechanism and it makes a false transfer, causing paper toweling from the reserve roll to be introduced into the feed mechanism. When this occurs, the feed mechanism can become jammed and no longer capable of dispensing paper toweling or simultaneously dispense paper toweling from both the primary and reserve rolls.
In another type multiple roll dispenser, the transfer assembly is a one-piece unit and includes a transfer arm having a pair of axially spaced transfer fingers and a sensing arm having a sensing surface. The transfer assembly is mounted for common pivotal movement and the sensing surface engages the outer surface of the toweling on the primary roll. The transfer assembly is arranged so that, by the time the sensing surface engages the primary roll core, the transfer arm has pivoted to a position where the transfer fingers push the leading end of the toweling from the reserve roll into the feed mechanism.